The present invention relates to a method for manufacturing a semiconductor device and a semiconductor device, and for example, can be used suitably for a semiconductor device that uses a group III-V compound semiconductor.
As the semiconductor laser (the semiconductor device) that operates at a high speed of 10 to 40 Gbs, a semiconductor material of an InGaAlAs system is used. Specifically, a semiconductor material of the InGaAlAs system is used for an active layer used as an optical waveguide. However, Al (aluminum) in the active layer is easily oxidized and the active layer deteriorates easily by oxidization of Al.
For this reason, for an antioxidant measure of Al, a configuration that adopts a cover layer for covering the active layer is being examined.
For example, Japanese Unexamined Patent Application Publication No. Hei9 (1997)-92925 discloses a semiconductor laser that has a MQW layer above a p-type InP substrate and further has an n-InP layer over this MQW layer.
Moreover, Japanese Unexamined Patent Application Publication No. 2004-14821 discloses a semiconductor laser that uses a (100) off substrate of GaAs.
Moreover, in “Low Drive-Current and Wide Temperature Operation of 1.3 μm AlGaInAs-MQW BH-DFB Lasers by Laterally Enhanced Cladding Layer Growth,” R. Kobayashi et al., OFC2008, OThK2 and Japanese Unexamined Patent Application Publication No. Hei5 (1993)-110208, semiconductor lasers formed by selective growth are disclosed; in “Optical property of InAsP/InP strained quantum wells grown on InP (111)B and (100) substrates,” H. Q. Houa et al., J. Appl. Phys., 75, 4673(1994), “Optical properties of In0.52Al0.48As layers and In0.53Ga0.47As/In0.52Al0.48 As quantum well structures grown on (111)B InP substrates by molecular beam epitaxy,” Y. Kawamural et al., IPRM1998, ThP-11, and “High CW output power InGaAs/InGaAsP/InGaP diode lasers: effect of substrate misorientation,” L. J. Mawst et al., LD conference 1995, SCL13.5, there are descriptions about growth of epitaxially grown films over inclined substrates.